Over the past year, the boycott, divestment, and sanctions (BDS) campaign has finally gained some widespread political attention in the United States: from the American Studies Association’s vote to endorse the academic boycott of Israel, to the flurry of student votes for divestment at the University of California and other US campuses, to the unprecedentedcriticism that met Scarlett Johansson when she quit her role as global ambassador for Oxfam so she could continue as global ambassador for SodaStream.

Last month’s protests at West Coast ports point not only to the momentum with which BDS has moved forward — more quickly than most activists could have predicted — but also to the possibility of direct action posing an ever graver threat to business as usual for Israel, particularly when organized labor is on board.

Until now, no one had ever kept an Israeli cargo ship from unloading for two consecutive days; we blocked the Zim Piraeus for four.

From Saturday, August 16 to Tuesday, August 19, activists at the Port of Oakland protested Israeli human rights abuses by picketing the berths where the ship intended to offload its cargo.

Zim Integrated Shipping Services isn’t just an Israeli shipping company. It’s the largest Israeli shipping company — the tenth largest in the world — and it’s intimately tied to the government, which owns a special stake in Zim (known as the “golden share”) and requires that it keep at least eleven ships at all times, to be used by the military in the case of national security emergencies.

Founded in 1945 by the Histadrut (the main Israeli trade union body) and the Jewish Agency, Zim functioned during the Nakba as the sole maritime connection for Zionist colonists and, subsequently, the nascent state of Israel. The Israeli government’s ownership of Zim has given the company monopoly power from the beginning: US loans going towards transportation, for example, would be earmarked for Zim, prompting one member of the Knesset in 1950 to remark that he “approve[s] the loan legislation, on condition that there is one law for all, and that all companies are treated equally with [government owned] Zim Shipping. . .. Zim has privileges which private companies don’t.”

Zim was privatized in 2004 when Israel Corp., owned by the Ofer Brothers Group, bought the government’s stake in the company for $115 million. But the government still retains its “golden share,” which gives it veto power over major share sales or other corporate actions.

The Palestinian General Federation of Trade Unions (PGFTU) has called on workers worldwide, and Bay Area workers in particular, to refuse to facilitate the commerce of Zim and other Israeli companies as part of BDS. This call was supported by COSATU, the Coalition of South African Trade Unions.

US unions have for the most part been slow to respond, due in part to the deep and longstanding influence of the Histadrut and its US counterpart, the Jewish Labor Committee (JLC). Formed as an anti-fascist solidarity group in 1934, the JLC has since the end of World War II taken the most reactionary positions on political (and particularly racial justice) issues, from supporting McCarthyite anti-communist, anti-Semitic witch-hunts in the 1950s, to demonizing the black freedom movement in the 1960s, to helping roll back affirmative action policies in the seventies, to supporting the US attacks on Vietnam and Iraq.

The organization is primarily concerned, however, with enforcing a pro-Israel line in elite labor and Democratic Party circles, including through its cozy relationship with the AFL-CIO. In 2009, the JLC co-founded the group Trade Unions Linking Israel and Palestine (TULIP), whose specific purpose is to prevent trade union support for BDS and undermine it where it already exists.

Given this political climate, it’s remarkable that this summer’s Block the Boat action in Oakland was able to succeed — and only due to mass community participation and solidarity from the rank and file of the Bay Area dockworkers’ union, the International Longshore and Warehouse Union (ILWU) Local 10. While the JLC and other Zionist organizations wield great influence over the AFL-CIO, the ILWU actually broke with the AFL-CIO as recently as August 2013. The union’s slogan is “An injury to one is an injury to all,” and their history bears out their commitment to international solidarity.

It was a strike by Local 10 that kept a South African ship from offloading its cargo for eleven days in 1984. In 1978, Local 10 refused to load weapons parts that were supposed to be sent to Chile’s brutal military dictatorship. During the Occupy protests, the union refused to work as part of the general strike called for by Occupy Oakland and other activists. Local 10 member Clarence Thomas traces the union’s history of honoring direct actions back eighty years: “[w]e’ve respected community picket lines since 1935, when Local 10 workers refused to load metal that was bound for the war machines of fascist Italy and Japan.”

Since sympathy strikes are illegal under the anti-labor Taft-Hartley Act, the union leadership itself couldn’t take a position in support of Block the Boat’s community picket. But the sympathies of the rank-and-file are nonetheless clear, nowhere more so than in the 2010 resolution (adopted by Local 10’s executive board) condemning Israel’s attack on the Mavi Marmara and declaring support for the PGFTU call for boycott. That year saw the first successful port action targeting an Israeli ship in 2010, when (in response to Israel’s massacre of nine activists aboard the Gaza aid flotilla Mavi Marmara) five hundred activists in Oakland prevented a Zim ship from unloading for a full day.

Then as now, the efforts of Oakland’s community in support of the Palestinian liberation movement would not have enjoyed such success without the support of the ILWU rank and file. According to Block the Boat organizer Lara Kiswani, executive director of the Arab Resource and Organizing Center (AROC), part of the reason for the successes of the Bay Area Palestine solidarity work lies in its history of engagement with organized labor: “The Arab and Palestinian community worked for over a decade to establish a relationship to the labor movement in the Bay Area.”

Indeed, Block the Boat had initially been planned for August 2, but AROC organizers pushed for it to be rescheduled to August 16 in order to give them time to develop their relationship with the union, as well as to bring out the Palestinian and other Arab leadership that has been central throughout protests against the Gaza massacre. Day after day, AROC and other activists went to the union hall to talk to the workers, to explain why they were carrying out the action, to answer their questions, and to ask for their support, in a continual process of engagement.

We also had the support of ILWU members who are community activists around many anti-racist struggles. The most important relationships weren’t with the union leadership, Kiswani says, but with the rank and file, who were supportive throughout the action: “[W]e even received phone calls and emails from ILWU workers providing us with vital information about the ship, its whereabouts and its anticipated departure.”

While Block the Boat was originally planned as a one-off, the success of the August 16 action (the Piraeus didn’t even attempt to dock) created such momentum that the effort broadened beyond the initial organizing. The community returned every day at 5 AM, and then again at 5 PM. Zim tried to wait it out — they even (apparently) tried to fake us out by making for Los Angeles and then doubling back to dock in a different berth, operated by Ports of America (PA).

The little cargo Zim managed to offload was, according to sources in the longshoremen’s union, a result of the duplicity of PA, which circumvented our picket by calling in longshoremen to work other ships before transferring them to the Piraeus. In 2010, Local 10 was under contract, which guaranteed they would be paid irrespective of their decision to strike. This time, however, they were without a contract, which meant they wouldn’t be paid if they refused to work. Still, every morning and every evening, Local 10 lived up to their values and reputation by refusing to cross our picket line.

We were told that, officially, the longshoremen wouldn’t cross because of “unsafe working conditions.” It wasn’t our picket that made the conditions unsafe, but rather, potential police reaction — union members pointed to a 2005 incident in which Oakland police shot workers crossing a picket line with rubber bullets. As long as our picket line was big enough, Local 10 would respect it.

The longshoremen kept their word. As midnight approached on Tuesday, August 19, we heard from several sources that those longshoremen who had been manipulated into working the Zim ship were planning to engage in a work slowdown, deliberately minimizing the amount of cargo they unloaded. The insistence of AROC and other activists that the Block the Boat coalition take the time to cultivate a relationship with labor based on trust and respect turned out to be crucial.

While some sloppy media reports alleged that the ship had successfully unloaded its cargo before leaving the Bay, sources told us that only a fraction of the 176 Oakland-bound containers were actually offloaded. One Port of Oakland official claimed twenty-six had been unloaded; other union sources said fifty. These figures remain unconfirmed, but regardless of the exact numbers, as the ship finally left it was clearly still laden with red containers, while no cargo was loaded onto it.

This information has since been confirmed by companies quoted as saying they’re reconsidering doing business with Zim in the wake of Block the Boat. It would certainly explain why it spent August 20 moored in the Bay instead of taking off immediately. Maybe it was waiting for us to leave before attempting to dock at another berth. At any rate, it wasn’t a decision Zim made lightly: one dockworker told us every twelve hours we delayed the Piraeus cost the company $50,000.

That figure, too, is still unconfirmed, but what we know for sure is that the lost revenue greatly exceeds the operating costs. After activists in Los Angeles, Tacoma, and Seattle also succeeded in delaying Zim ships, it’s clear that Block the Boat isn’t just a flash in the pan: doing business with Zim can cause significant delays, and customers who don’t want to deal with that will take their business elsewhere.

So it appears that, as a BDS tactic, Block the Boat has legs. And it’s no surprise that it was kicked off in the Bay Area, a hotbed of Palestinian and Palestine solidarity activism. University of California Berkeley and University of California Davis, for example, were home to two of the earliest chapters of Students for Justice in Palestine (SJP), an organization of which I am a member. In 2002, Berkeley hosted the first National SJP Conference. Since then, SJP chapters have been at the vanguard of BDS campaigns (specifically focused on divestment) at universities across the United States.

Kiswani, herself one of the co-founders of SJP at Davis, says the strength and vision of pro-Palestinian organizing in the Bay Area is attributable, in part, to the painstaking work of building coalitions across movements: “The organizing that led up to the Block the Boat action in Oakland included the leadership of AROC and that of Arabs and Palestinians,” she told me, “but also involved the leadership of organizers that work on issues of policing, militarization, anti-war, economic, housing, and racial justice.”

The growing success of BDS — through divestment initiatives, Block the Boat, or other direct actions — depends on precisely these kinds of relationships. As this action showed, no single relationship is more crucial to the effectiveness of BDS than its relationship to organized labor. BDS isn’t just about isolating Israel. It’s also about normalizing that isolation, so that every dollar Zim loses due to delays or spoiled goods carries with it the threat of much greater losses.

Zim is already in dire financial straits, requiring a gigantic restructuring plan that would, among other things, write off $1.4 billion of the company’s $3.4 billion debt. Israel regards Zim as vital to national security, and not just because of its golden share or those eleven ships. The Israeli government’s ability to preserve its regime of ethnic cleansing and apartheid ultimately depends on its smooth integration into the global capitalist system.

Corporations like Zim are lifelines that tie Israel to the “international community” of global trade. The Israeli economy is heavily dependent on exports, mostly to the US and Europe: A 2011 meeting of Israeli capitalists concluded that, if government policy doesn’t change dramatically, Israel eventually will face isolation on the order of what ended apartheid South Africa.

One of Israel’s largest global industries is the repression industry. Israel plays a critical role in supplying repressive regimes — from Pinochet to the Argentinean junta to the South African apartheid government, from the United States to Brazil to India — with the technology, weapons, strategies, and methods of repression that they need to repress their own populations and gain political and economic power through the exploitation of people and land across the globe.

However, beyond the war economy, according to the Israel Export Institute, “a worrying picture”: Israeli exports to the US have been declining for five consecutive quarters, falling 7 percent in the second quarter of 2014. The Palestine solidarity movement is moving from strength to strength. The protests of Zim, as the last big solidarity action in the wake of Israel’s counterinsurgency operation in the Gaza Strip, makes clear how ripe the situation is for an escalation of BDS action in the US and worldwide.

The keys to escalating BDS lie at the intersections of struggles. The progressive currents in organized labor are in many cases already sympathetic to Palestinians. It’s up to activists to reciprocate by being precise in our work, and ever mindful of the pressures union workers are under and their experience of corporate power.

It’s up to everyone who stands in solidarity with Palestinians to make connections. The Zim line imports Israeli-made ammunition into the US for use by police and the military. The bullets Israel routinely uses to kill Palestinians with impunity are the same bullets the US uses to kill black and brown people from Oakland to Ferguson to Afghanistan.

Zim is a key material link between the purveyors and the executors of imperial violence, between racist state repression at home and abroad. This year as last year, SWAT teams and military contractors from around the world convened in Oakland for the annual “Urban Shield” global training exercise and weapons expo. Like other such events, Israelis feature prominently at Urban Shield, often advertising their wares as field-tested on Palestinians.

This year, Urban Shield was met with fierce resistance from a coalition of hundreds of activists, from those organizing against local police brutality and mass incarceration to those organizing against Israeli militarism and apartheid.

Oakland won’t be hosting Urban Shield next year. And a glance at the Zim Pacific line’s schedule indicates there will be no Zim ships docking in California — not in the Bay Area, and not in Los Angeles — after the next Oakland Block the Boat action on October 25.